Abstract: AIM: To observe the effects of repeated intravenous administration of fentanyl 1 μg/kg on fentanylinduced coughing during anesthesia induction. METHODS: 300 patients with ASA Ⅰor Ⅱ for elective procedures, received an intravenous injection of fentanyl 1 μg/kg via a peripheral cannula prior to anesthesia induction.The patients who experienced cough were randomly divided into two equal groups according to the interval of repeated administration:group 2 min received the same dosage of fentanyl 2 min later and group 5 min was administrated the same dosage of fentanyl 5 min later.The occurrence of cough was recorded.The level of cough was graded. RESULTS: The incidence of fentanyl-induced cough in the first administration was 18% (54/300).After repeated administration, the occurance of cough in group 2 min (0%, 0/27) was lower than that in group 5 min (40.7%, 11/27) (P<0.01).There was significant difference on the severity between two groups (P<0.01). CONCLUSION: The incidence of fentanyl-induced coughing was significantly decreased after repeated administration of fentanyl 1 μg/kg during anesthesia induction, but the incidence of cough may be increased with the prolonging of the dosing interval.

Key words: fentanyl, cough, repeated administration